ExodusTimeSequenceStepper

Solves the Transient problem at a sequence of time points taken from a specified exodus file.

The Exodus file is read by the first process (rank 0), and the time step sequence is then broadcast to all other processes.

If the solve fails to converge during a time step, the behavior of the ExodusTimeSequenceStepper is the same as the TimeSequenceStepper. The time step will be cut then the time stepper will attempt to return to the original sequence.

Example input file

In this example, the time stepper extracts the time sequence from an exodus output file. This exodus file may not necessarily have been generated using the same input file. The starting and end time of the simulation may still be set independently.

[Executioner]
  type = Transient
  end_time = 4.0
  [./TimeStepper]
    type = ExodusTimeSequenceStepper
    mesh = timesequence_no_start_time.e
  [../]
[]

Input Parameters

meshThe name of the mesh file to extract the time sequence from (must be an exodusII file).
C++ Type:MeshFileName
Controllable:No
Description:The name of the mesh file to extract the time sequence from (must be an exodusII file).

Required Parameters

cutback_factor_at_failure0.5Factor to apply to timestep if a time step fails to converge.
Default:0.5
C++ Type:double
Controllable:No
Description:Factor to apply to timestep if a time step fails to converge.
reset_dtFalseUse when restarting a calculation to force a change in dt.
Default:False
C++ Type:bool
Controllable:No
Description:Use when restarting a calculation to force a change in dt.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.

Advanced Parameters

(../../../SoftwareDownloads/moose/test/tests/time_steppers/timesequence_stepper/exodustimesequence.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax =  1
  ymin = -1
  ymax =  1
  nx = 2
  ny = 2
  elem_type = QUAD9
[]

[Functions]
  [./exact_fn]
    type = ParsedFunction
    value = t*t*(x*x+y*y)
  [../]

  [./forcing_fn]
    type = ParsedFunction
    value = 2*t*(x*x+y*y)-4*t*t
  [../]
[]

[Variables]
  [./u]
    family = LAGRANGE
    order = SECOND
  [../]
[]

[ICs]
  [./u_var]
    type = FunctionIC
    variable = u
    function = exact_fn
  [../]
[]

[Kernels]
  [./td]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    boundary = 'left right top bottom'
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient
  end_time = 4.0
  [./TimeStepper]
    type = ExodusTimeSequenceStepper
    mesh = timesequence_no_start_time.e
  [../]
[]

[Outputs]
  exodus = true
[]

Example input file
Input Parameters